Abstract:

Discrete modeling of particle-fluid interaction was of great importance for its wide applications in chem- ical, petroleum and geotechnical engineering. Using Immersed Boundary Method (IBM) to couple Discrete Element Method (DEM) with Lattice Boltzmann Method (LBM) was adopted by many researchers to study particle-fluid systems. However, to accurately simulate the behavior of a large number of particles in the fluid, a huge computational power wasrequired to fully resolved the motion of each particle and an in- tensive search of particles’ contacts was needed to account for the collision between particles. In this paper, a periodic boundary was proposed for coupling DEM with LBM using IBM and an efficient particle contact detection algorithm was developed to further reduce the computation cost. The model was val- idated by several well-defined benchmark including: a single particle settling in a box, particle spinning in a channel and the well-known ‘Drafting, Kissing and Tumbling’ (DKT) effect of two settling disks. The model’s applicability was exhibited in the simulation of sediments movement in a channel, which agreed well with previous experiments. These results showed the potential usage of present numerical model to investigate in particle-fluid interaction systems.

摘要:

颗粒-流体相互作用的离散建模在化工、石油和岩土工程等领域有着广泛的应用。采用浸没边界法(IBM)耦合离散元法(DEM)和格点玻尔兹曼法(LBM)是许多研究者研究颗粒-流体系统所采用的方法。然而，要精确地模拟流体中大量粒子的行为，需要一个巨大的计算能力来完全解决每个粒子的运动，并需要对粒子之间的碰撞进行深入的搜索。本文利用IBM提出了DEM与LBM耦合的周期边界，并开发了一种有效的粒子接触检测算法，进一步降低了计算成本。该模型被一些定义明确的基准验证，包括:一个单一的粒子在一个盒子里沉降，粒子在一个通道中旋转，以及众所周知的两个沉降盘的“牵引力、接吻和翻滚”(DKT)效应。该模型在河道泥沙运动模拟中具有较好的适用性，与前期实验结果吻合较好。这些结果显示了本数值模型在研究颗粒-流体相互作用系统中的潜在应用。

  （DOI: 10.1016/j.compfluid.2020.104613, SCI, IF=2.252,2区）